Assessment of hot-springs and geothermal prospects for sustainable energy goals

Abstract

Demand and search for green energy options that are both local and sustainable have significantly grown in the recent decade. This paper uses a new approach integrating subjective and objective multi-criteria decision-making (MCDM) techniques to assess geothermal resources in Odisha, India. A geothermal prospect map for the area was created by combining eight key factors: heat flow, geothermal gradient, geology, Curie Point Depth (CPD), seismic activity, structural density, crustal thickness, and sediment thickness. Heat flow is closely correlated with the geothermal gradient, crustal thickness, and rock composition. Approximately 22.32% of the studied area shows very high potential for geothermal resources, with an additional 17.05% exhibiting considerable potential. The receiver operating characteristic (ROC) curve demonstrates favourable outcomes, as seen by an area under the curve (AUC) of approximately 0.682. The fracture zone near the hot spring extends deeply, likely acting as a conduit for fluid circulation, driven by heat from radioactive decay or elevated thermal gradients at basement depths. The average reservoir temperatures of thermal springs in Odisha are estimated to be around 110 ± 5°C, and the geothermal water rises from a depth of 1.37 ± 0.32 km. The results offer valuable insights to the agencies involved in renewable energy exploration and development by assisting them in the identification of prospective alternative energy sources within the study area. Furthermore, utilizing geothermal energy can significantly decrease CO₂ emissions, supporting India's net-zero emissions goal by 2070 while simultaneously stimulating local economy and strengthening energy independence.